<template>
  <div class="el-tree-select">
    <el-select
      ref="treeSelect"
      v-model="valueId"
      style="width: 100%"
      :filterable="true"
      :clearable="true"
      :filter-method="selectFilterData"
      :placeholder="placeholder"
      @clear="clearHandle"
    >
      <el-option :value="valueId" :label="valueTitle">
        <el-tree
          id="tree-option"
          ref="selectTree"
          :accordion="accordion"
          :data="options"
          :props="objMap"
          :node-key="objMap.value"
          :expand-on-click-node="false"
          :default-expanded-keys="defaultExpandedKey"
          :filter-node-method="filterNode"
          @node-click="handleNodeClick"
        />
      </el-option>
    </el-select>
  </div>
</template>

<script setup>

const { proxy } = getCurrentInstance();

const props = defineProps({
	/* 配置项 */
	objMap: {
		type: Object,
		default: () => {
			return {
				value: 'id', // ID字段名
				label: 'label', // 显示名称
				children: 'children' // 子级字段名
			};
		}
	},
	/* 自动收起 */
	accordion: {
		type: Boolean,
		default: () => {
			return false;
		}
	},
	/** 当前双向数据绑定的值 */
	value: {
		type: [String, Number],
		default: ''
	},
	/** 当前的数据 */
	options: {
		type: Array,
		default: () => []
	},
	/** 输入框内部的文字 */
	placeholder: {
		type: String,
		default: ''
	}
});

const emit = defineEmits(['update:value']);

const valueId = computed({
	get: () => props.value,
	set: (val) => {
		emit('update:value', val);
	}
});
const valueTitle = ref('');
const defaultExpandedKey = ref([]);

function initHandle() {
	nextTick(() => {
		const selectedValue = valueId.value;
		if(selectedValue !== null && typeof (selectedValue) !== 'undefined') {
			const node = proxy.$refs.selectTree.getNode(selectedValue);
			if (node) {
				valueTitle.value = node.data[props.objMap.label];
				proxy.$refs.selectTree.setCurrentKey(selectedValue); // 设置默认选中
				defaultExpandedKey.value = [selectedValue]; // 设置默认展开
			}
		} else {
			clearHandle();
		}
	});
}
function handleNodeClick(node) {
	valueTitle.value = node[props.objMap.label];
	valueId.value = node[props.objMap.value];
	defaultExpandedKey.value = [];
	proxy.$refs.treeSelect.blur();
	selectFilterData('');
}
function selectFilterData(val) {
	proxy.$refs.selectTree.filter(val);
}
function filterNode(value, data) {
	if (!value) return true;
	return data[props.objMap['label']].indexOf(value) !== -1;
}
function clearHandle() {
	valueTitle.value = '';
	valueId.value = '';
	defaultExpandedKey.value = [];
	clearSelected();
}
function clearSelected() {
	const allNode = document.querySelectorAll('#tree-option .el-tree-node');
	allNode.forEach((element) => element.classList.remove('is-current'));
}

onMounted(() => {
	initHandle();
});

watch(valueId, () => {
	initHandle();
});
</script>

<style lang='scss' scoped>
@import "@/assets/styles/variables.module.scss";
.el-scrollbar .el-scrollbar__view .el-select-dropdown__item {
  padding: 0;
  background-color: #fff;
  height: auto;
}

.el-select-dropdown__item.selected {
  font-weight: normal;
}

ul li .el-tree .el-tree-node__content {
  height: auto;
  padding: 0 20px;
  box-sizing: border-box;
}

:deep(.el-tree-node__content:hover),
:deep(.el-tree-node__content:active),
:deep(.is-current > div:first-child),
:deep(.el-tree-node__content:focus) {
  background-color: mix(#fff, $--color-primary, 90%);
  color: $--color-primary;
}
</style>